An incoming Conservative government would take steps to cut the vetting database down to size and would balk at 'pre-crime' behavioural vetting techniques.

Tory opposition to key elements of the Vetting and Barring process proposed by the Independent Safeguarding Authority (ISA) emerged last night at a meeting of the Conservative Technology Forum, which met in the House of Commons to discuss issues around individual's ownership of their data.

The scheme has excited some controversy over the last few months, both for the likely extent of its coverage and because, according to leaked guidelines, it is the intention of the ISA not only to hold data on past criminal activity, but also to score individuals on the basis of their attitudes and beliefs.

Tory tech guru Liam Maxwell, who addressed the meeting, said that he was utterly opposed to the use of scoring in this way and that it was "just wrong". He added that while the Technology Forum was not a policy-making body, "we will be having words with Dominic".

Dominic Grieve is currently Shadow Minister for Justice and has been closely involved in the development of Conservative policy on data and privacy.

While this comment was not directed exclusively towards the vetting database, it would clearly have major implications for it.

Other speakers noted that dealing with individuals on the basis of what they might do in future lay at the heart of the Government’s Onset programme, for young people – and that the EU had also demonstrated a disturbing interest in such approaches.

According to a report by journalist Josie Appleton, the ISA has decided to put in place a scoring system to be filled in by its army of trained bureaucrats. Items will be assessed on the basis of "whether relevant conduct or a risk of harm 'on the face of it' seems to have occurred".

She adds: "The case worker will examine... 'predisposing factors', such as 'those factors relating to an individual’s interests or drives'; 'cognitive factors', such as 'strong anti-social beliefs'; and 'behavioural factors', including 'using substances or sex to cope with stress or impulsive, chaotic or unstable lifestyle. Drug use, sex life, favourite films'."

The guidelines were leaked two months ago, but have subsequently disappeared from public view. However, the ISA did confirm the intention to use behavioural vetting.

An ISA spokesman today said that it was "part of the structured judgement process" and "one element within a five stage process". He went on to say: "Secondly, as you rightly pointed out, the ISA can not comment on the purely hypothetical situation you outlined, ie what members of the Tory Front may or may not think or what may or may not happen in the event of a change of Government." ®